Conventionally, a motor in which permanent magnets are mounted on a rotor is known. This kind of motor is broadly classified as a surface magnet type motor (see, for example, patent reference 1) in which permanent magnets are attached to a surface of a rotor, or a permanent magnet embedded type motor in which permanent magnets are embedded in a rotor. In the permanent magnet embedded type motor, magnet insertion holes are formed in a rotor core, and the permanent magnets are disposed in the magnet insertion holes. A magnet holding portion (a protrusion) is provided in the magnet insertion hole for positioning the permanent magnet so as to prevent the permanent magnet from moving in the magnet insertion hole.